Forward/WMG
Someone is attempting to clone psychics or grow psychic organs, and Dumant was part of the process.
The Operative was apparently after the same organ-growth tech that Dumont was behind, and he's already been shown both working with the remnants of the Browncoats and is interested heavily in using River's psychic abilities. It would make sense that whatever Dumant was doing, it involved psychics if the Operative's people were after it too.
The Operative was cloning psychics
Working on the above, the soldiers attacking Dumont's mansion were working for the Operative, and were after the cloned organs. And considering that he's working for some aspect of the resistance now, it seems the Browncoats are trying to make their own psychics to fight the Academy's creations.
Wash survived because Xander dressed up as him in the Halloween Episode.
See this fanfic. In it, Xander dresses up as Wash for halloween, and we are unfortunately spared lots of fetish fuel as Cordelia dresses up as Zoe. They both end up turning into their costumes, and Zoe tells Wash/Xander that the real Wash died during the landing. After the halloween spell was reversed, Wash and Zoe were both transported back to their own bodies, and Wash-unconsciously sensing his imminent death-turned in his chair and the spear just barely missed him. Admit it. You're as glad as me that Wash and Book aren't dead.
Doctor al-Rashid is an Assassin.
Black robes, red sash, just liek the leader of the Assassins tends to wear? Check. Kindly-sounding Arabic man? Check. Word of God that his voice sounds like Peter Reneday, who voices al-Mualim in Assassin's Creed? Check. All he needs is a hidden blade.
The American is Jayne's uncle
He's referred to as "Andy," which matches up with the uncle that taught Jayne his survival skills. Andy isn't just reluctant to kill him, he clearly knows him ahead of time. He knows Jayne is dangerous, evidenced by how he thinks in terms of minimizing both sets of casualties. This also adds a whole new dimension to Vera, since she's referred to as Andy's gun repeatedly.
- The chapter titles seem to be counting down the number of members of the Rifles who are still active. Interestingly, they seem to imply the first man that the Six "lose" is Andy, as the chapter where he has Jayne in his sights and deliberately misses is titled "The Five."